The invention relates to a fuel injection pump for internal combustion engine having a supply pump which is controlled by a pressure control valve and is also controlled to generate an rpm-dependent pressure. An adjusting member of an rpm governor is also provided for additionally varying the pressure in accordance with load. In a known fuel injection pump of this kind, the load-dependent change in the pressure is attained via an adjusting sleeve of the centrifugal rpm governor, which, however, only indirectly engages a governor lever which actuates the quantity control member of the pump. The pressure thus corresponds to the injection quantity only when the adjusting sleeve and the governor lever are in direct, force-locking communication and furthermore when no additional control members are disposed between the two, such as adaptation springs and the like. In a different, known fuel injection pump, the change in pressure is effected by means of a pressure control valve engaged by an adjusting magnet. In the specialized instance, the adjusting magnet engages the pressure control valve spring on the side remote from the control slide and varies the initial stressing of the spring in a load-dependent manner.
In still another different known fuel injection pump, the pressure is controlled in accordance with temperature by permitting the discharge of partial quantities of fuel. However, it has also already been suggested that the pressure be additionally controlled via magnetic valves which control the flow of a quantity of fuel either in or out. In all the known systems, the supplemental or redundant pressure control serves the purpose of varying the injection onset, because the supply pump pressure is exerted upon a piston whose purpose is injection onset adjustment. These known supplemental control means are relatively expensive and require additional independent means, such as a specialized closed control loop.